Cooling device for removing heat from subcutaneous lipid-rich cells

ABSTRACT

A cooling device for removing heat from subcutaneous lipid-rich cells of a subject having skin is provided. The cooling device includes a support having a first portion and a second portion. A first cooling element having a first heat exchanging surface is located at the first portion of the support. A second cooling element having a second heat exchanging surface is located at the second portion of the support. At least one of the first and second cooling elements is movable along the support and is configured to rotate for adjusting an angle between the first and second heat exchanging surfaces.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent application Ser. No. 13/616,497, filed Sep. 14, 2012, which is a continuation of U.S. patent application Ser. No. 12/942,852, filed Nov. 9, 2010, now U.S. Pat. No. 8,337,539, which is a divisional of U.S. patent application Ser. No. 11/359,092, filed Feb. 22, 2006, now U.S. Pat. No. 7,854,754, the disclosures of which are incorporated herein by reference in their entireties.

TECHNICAL FIELD

The present application relates to cooling devices, systems, and methods for removing heat from subcutaneous lipid-rich cells.

BACKGROUND

As statistics have shown, excess body fat increases the likelihood of developing various types of diseases such as heart disease, high blood pressure, osteoarthrosis, bronchitis, hypertension, diabetes, deep-vein thrombosis, pulmonary emboli, varicose veins, gallstones, hernias, and several other conditions.

In addition to being a serious health risk, excess body fat can also detract from personal appearance and athletic performance. For example, excess body fat can form cellulite that causes an “orange peel” effect at the surface of the skin. Cellulite forms when subcutaneous fat protrudes into the dermis and creates dimples where the skin is attached to underlying structural fibrous strands. Cellulite and excessive amounts of fat are often considered to be unappealing. Thus, in light of the serious health risks and aesthetic concerns associated with excess fat, an effective way of controlling excess accumulation of body fat is urgently needed.

Liposuction is a method for selectively removing body fat to sculpt a person's body. Liposuction is typically performed by plastic surgeons using specialized surgical equipment that mechanically removes subcutaneous fat cells via suction. One drawback of liposuction is that it is a serious surgical procedure, and the recovery may be painful. Liposuction can have serious and occasionally even fatal complications. In addition, the cost for liposuction is usually substantial.

Conventional non-invasive treatments for removing excess body fat typically include topical agents, weight-loss drugs, regular exercise, dieting, or a combination of these treatments. One drawback of these treatments is that they may not be effective or even possible under certain circumstances. For example, when a person is physically injured or ill, regular exercise may not be an option. Similarly, weight-loss drugs or topical agents are not an option when they cause an allergic or negative reaction. Furthermore, fat loss in selective areas of a person's body cannot be achieved using weight-loss drugs.

Other non-invasive treatment methods include applying heat to a zone of subcutaneous lipid-rich cells. U.S. Pat. No. 5,948,011 discloses altering subcutaneous body fat and/or collagen by heating the subcutaneous fat layer with radiant energy while cooling the surface of the skin. The applied heat denatures fibrous septa made of collagen tissue and may destroy fat cells below the skin, and the cooling protects the epidermis from thermal damage. This method is less invasive than liposuction, but it still can cause thermal damage to adjacent tissue.

Another promising method of reducing subcutaneous fat cells is to cool the target cells as disclosed in U.S. Patent Publication No. 2003/0220674, the entire disclosure of which is incorporated herein. This publication discloses, among other things, reducing the temperature of lipid-rich subcutaneous fat cells to selectively affect the fat cells without damaging the cells in the epidermis. Although this publication provides promising methods and devices, several improvements for enhancing the implementation of these methods and devices would be desirable.

U.S. Patent Publication No. 2003/0220674 also discloses methods for selective removal of lipid-rich cells, and avoidance of damage to other structures including dermal and epidermal cells. A method for inducing collagen compaction, remodeling and formation is also needed for treatment of loose or sagging skin, age- or sun-damaged skin or a variety of other skin disorders. Therefore, a method for simultaneously removing lipid-rich cells while providing beneficial collagen effects is also needed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a system for removing heat from subcutaneous lipid-rich cells in accordance with an embodiment of the invention.

FIGS. 2A, 2B and 2C are isometric views of a cooling device for removing heat from subcutaneous lipid-rich cells in accordance with embodiments of the invention.

FIG. 3A is an end view and FIG. 3B is a side cross-sectional view partially illustrating a cooling device for removing heat from subcutaneous lipid-rich cells in accordance with an embodiment of the invention.

FIG. 4 is a side elevation view illustrating a cooling device having thermoelectric cooling elements in accordance with another embodiment of the invention.

FIGS. 5A and 5B are side elevation views of a cooling device having curved heat exchanging surfaces in accordance with another embodiment of the invention.

FIG. 6 is a block diagram showing computing system software modules for removing heat from subcutaneous lipid-rich cells.

DETAILED DESCRIPTION A. Overview

The present disclosure describes devices, systems, and methods for cooling subcutaneous lipid-rich cells. The term “subcutaneous tissue” means tissue lying underneath the dermis and includes adipocytes (fat cells) and subcutaneous fat. It will be appreciated that several of the details set forth below are provided to describe the following embodiments in a manner sufficient to enable a person skilled in the relevant art to make and use the disclosed embodiments. Several of the details and advantages described below, however, may not be necessary to practice certain embodiments of the invention. Additionally, the invention can include other embodiments that are within the scope of the claims but are not described in detail with respect to FIGS. 1-6.

One aspect is directed toward a cooling device for removing heat from subcutaneous lipid-rich cells. The cooling device includes a support with a first portion and a second portion, a first cooling element having a first heat exchanging surface, and a second cooling element having a second heat exchanging surface. The first cooling element is located at the first portion of the support, and the second cooling element is located at the second portion of the support. At least one of the first and second cooling elements is movable along the support, and at least one of the first and second cooling elements is configured to rotate for adjusting an angle between the first and second heat exchanging surfaces. The first and second cooling elements, for example, can be rotatable either in two dimensions or in three dimensions. The cooling elements can use a number of cooling technologies including thermoelectric coolers, recirculating chilled fluid, vapor compression elements, or phase change cryogenic devices. One skilled in the art will recognize that there are a number of other cooling technologies that could be used and that the cooling elements need not be limited to those described here. Further aspects include that the cooling device can be configured as a handheld device.

Another aspect is directed toward a cooling device having a cooling member using thermoelectric principles or other cooling technologies. The cooling device also includes a heat dissipating member in thermal communication with the cooling member and an interface member having a heat exchanging surface configured to contact a subject's skin. The cooling member can be capable of reducing a temperature of a region such that lipid-rich cells in the region are affected while non-lipid-rich cells are not generally affected. Further aspects include that the heat exchanging surface can be a curved surface for concentrating the cooling effects.

Another aspect is directed toward a method of applying a cooling device having two cooling elements rotatable relative to each other. The cooling elements can have heat exchanging surfaces capable of removing heat from the subject's skin. The method includes rotating the cooling elements to achieve a desired orientation between the two heat exchanging surfaces, cooling the heat exchanging surfaces of the two cooling elements to a desired temperature, placing the cooled heat exchanging surfaces proximate to the subject's skin, and reducing a temperature of a region such that lipid-rich cells in the region are affected while non-lipid-rich cells in the epidermis are not generally affected. Further aspects include holding the cooling device by at least one hand of an operator.

Another aspect is directed toward a system for removing heat from subcutaneous lipid-rich cells. The system includes a cooling device having two rotatable cooling elements capable of achieving a desired orientation between each other, and a heat sink coupled to the cooling device to dissipate heat generated by the cooling device. When placed proximate to a subject's skin, the two cooling elements can be capable of reducing a temperature of a region such that lipid-rich cells in the region are affected while non-lipid-rich cells in the epidermis and/or dermis are not generally affected. Further aspects include that the cooling device can be configured as a handheld device.

B. System for Selectively Reducing Lipid-Rich Cells

FIG. 1 is an isometric view of a system 100 for removing heat from subcutaneous lipid-rich cells of a subject 101 in accordance with an embodiment of the invention. The system 100 can include a cooling device 104 placed at an abdominal area 102 of the subject 101 or another suitable area for removing heat from the subcutaneous lipid-rich cells of the subject 101. Various embodiments of the cooling device 104 are described in more detail below with reference to FIGS. 2-5B.

The system 100 can further include a cooling unit 106 and fluid lines 108 a-b connecting the cooling device 104 to the cooling unit 106. The cooling unit 106 can remove heat from a coolant to a heat sink and provide the chilled coolant to the cooling device 104 via the fluid lines 108 a-b. Examples of the circulating coolant include water, glycol, synthetic heat transfer fluid, oil, a refrigerant and any other suitable heat conducting fluids. The fluid lines 108 a-b can be hoses or other conduits constructed from polyethylene, polyvinyl chloride, polyurethane, and other materials that can accommodate the particular circulating coolant. The cooling unit 106 can be a refrigeration unit, a cooling tower, a thermoelectric chiller, or any other device capable of removing heat from a coolant.

As explained in more detail below, the cooling device 104 can include one or more thermoelectric cooling elements, such as Peltier-type thermoelectric elements. In such cases, the system 100 can further include a power supply 110 and a processing unit 114 operatively coupled to the cooling device 104. In one embodiment, the power supply 110 can provide a direct current voltage to the cooling device 104 to effectuate a heat removal rate from the subject 101. The processing unit 114 can monitor process parameters via sensors (not shown) placed proximate to the cooling device 104 and adjust the heat removal rate based on the process parameters. The processing unit 114 can include any processor, Programmable Logic Controller, Distributed Control System, and the like.

In another aspect, the processing unit 114 can be in electrical communication with an input device 118, an output device 120, and/or a control panel 122. The input device 118 can include a keyboard, a mouse, a touch screen, a push button, a switch, a potentiometer, and any other devices suitable for accepting user input. The output device 120 can include a display screen, a printer, a medium reader, an audio device, and any other devices suitable for providing user feedback. The control panel 122 can include indicator lights, numerical displays, and audio devices. In the embodiment shown in FIG. 1, the processing unit 114, power supply 110, control panel 122, cooling unit 106, input device 118, and output device 120 are carried by a rack 124 with wheels 126 for portability. In another embodiment, the various components can be fixedly installed at a treatment site.

One expected advantage of the system 100 is that the cooling device 104 can be applied to the subject 101 irrespective of the current physical condition of the subject 101. For example, the system 100 can be applied even when the subject 101 is not ambulatory or is ill. Another expected advantage is that the system 100 can remove or affect fat non-invasively without piercing the skin of the subject 101. Yet another expected advantage is that the system 100 is compact and can be used in an outpatient facility or a doctor's office. A further expected advantage is that the system 100 can quickly cool lipid-rich cells in a subcutaneous layer without requiring high-voltage power supplies.

C. Cooling Devices with Rotatable Cooling Elements

FIG. 2A is an isometric view of a cooling device 104 in accordance with one example of the invention suitable for use in the system 100. In this example, the cooling device 104 includes a support 128 having a first portion 129 a and a second portion 129 b, a first cooling element 130 a located at the first portion 129 a, and a second cooling element 130 b located at the second portion 129 b. The cooling device 104 is generally configured to be a handheld unit for manual operation, and/or it can be strapped or otherwise configured to be releasably attached to the subject. The first cooling element 130 a and/or the second cooling element 130 b can be configured to move along the support 128 and/or rotate to position the cooling elements 130 a-b for applying pressure to the treatment area during operation. These features are described in more detail below with reference to specific examples of the cooling devices.

The first and second cooling elements 130 a-b can have many similar features. As such, the features of the first cooling element 130 a are described below with reference symbols followed by an “a”, and corresponding features of the second cooling element 130 b are shown and noted by the same reference symbol followed by a “b.” The first cooling element 130 a can include a housing 139 a and fluid ports 138 a-b coupled to the fluid lines 108 a-b. The housing 139 a can be constructed from polymeric materials, metals, ceramics, woods, and/or other suitable materials. The example of the housing 139 a shown in FIG. 2A is generally rectangular but it can have any other desired shape.

The first cooling element 130 a can further include a first interface member 132 a having a first heat exchanging surface 131 a for transferring heat to/from the subject 101. In one example, the first heat exchanging surface 131 a is generally planar, but in other examples, the first heat exchanging surface 131 a is non-planar (e.g., curved, faceted, etc.) The first interface member 132 a can be constructed from any suitable material with a thermal conductivity greater than 0.05 Watts/Meter ° Kelvin, and in many examples, the thermal conductivity is more than 0.1 Watts/Meter ° Kelvin. Examples of suitable materials include aluminum, other metals, metal alloys, graphite, ceramics, some polymeric materials, composites, or fluids contained in a flexible membrane. As further described below with reference to FIGS. 4, 5A and 5B, portions of the first heat exchanging surface 131 a can be an insulating material with a thermal conductivity less than 0.05 Watts/Meter ° Kelvin.

The first cooling element 130 a can also include at least one sensing element 135 a proximate to the first heat exchanging surface 131 a. The sensing element 135 a, for example, can be generally flush with the heat exchanging surface 131 a. Alternatively, it may be recessed or protrude from the surface. The sensing element 135 a can include a temperature sensor, a pressure sensor, a transmissivity sensor, a bio-resistance sensor, an ultrasound sensor, an optical sensor, an infrared sensor, or any other desired sensor. In one example, the sensing element 135 a can be a temperature sensor configured to measure the temperature of the first heat exchanging surface 131 a and/or the temperature of the skin of the subject 101. For example, the temperature sensor can be configured as a probe or as a needle that penetrates the skin during measurement. Examples of suitable temperature sensors include thermocouples, resistance temperature devices, thermistors (e.g., neutron-transmutation-doped germanium thermistors), and infrared radiation temperature sensors. In another example, the sensing element 135 a can be an ultrasound sensor configured to measure crystallization of subcutaneous fat in the treatment region of a subject. In yet another example, the sensing element 135 a can be an optical or infrared sensor configured to monitor an image of the treatment region to detect, for example, epidermal physiological reactions to the treatment. The sensing element 135 a can be in electrical communication with the processing unit 114 via, for example, a direct wired connection, a networked connection and/or a wireless connection.

The cooling device 104 can further include a mounting element 136 a that couples the first cooling element 130 a to the first portion 129 a of the support 128. The mounting element 136 a, for example, can be a pin, a ball joint, a bearing, or other types of rotatable joints. Suitable bearings include, but are not limited to, ball bearings, roller bearings, thrust bearings, and journal bearings. The mounting element 136 a can accordingly be configured to rotatably couple the first cooling element 130 a to the support 128. In certain embodiments, the first cooling element 130 a can rotate relative to the support 128 in two dimensions (indicated by arrow A) such that the angle between the first and second heat exchanging surfaces 131 a-b can be adjusted. In another embodiment, the first cooling element 130 a can rotate in three dimensions relative to the support 128 (as indicated by arrows A and B).

A specific example of the mounting element 136 a includes a first mounting base 134 a and a flange 137 a coupled to the base 134 a by a rotatable or pivotable joint. By rotatably mounting at least one of the first and second cooling elements 130 a-b to the support 128, the angle between the first and second heat exchanging surfaces 131 a-b can be adjusted. For example, as shown in FIG. 2A, the first and second cooling elements 130 a-b can be generally parallel to each other, i.e., have an angle of generally 0° between the first and second heat exchanging surfaces 131 a-b. As shown in FIG. 2B, the first and second cooling elements 130 a-b can be generally co-planar, i.e., have an angle of generally 180° between the first and second heat exchanging surfaces 131 a-b. With the rotatable mounting elements 136 a-b, any angle of about 0° to about 180° between the first and second heat exchanging surfaces 131 a-b can be achieved.

The cooling device 104 can further include a shaft 133, and the first mounting base 134 a can be attached to the shaft 133. As explained in more detail below, at least one of the cooling elements 130 a-b moves along the shaft 133 and/or the shaft 133 moves relative to the support 128 to adjust the distance between the first and second cooling elements 130 a-b (shown by arrow C). The shaft 133, more specifically, extends between the first and second cooling elements 130 a-b to enable movement of at least one of the cooling elements 130 a-b relative to the support 128. In the embodiment shown in FIG. 2A, the first mounting base 134 a is fixedly attached to the shaft 133, and a second mounting base 134 b of the second cooling element 130 b is configured such that the second mounting base 134 b can slide along the shaft 133. In other embodiments, both the first mounting base 134 a and the second mounting base 134 b can be configured to slide along the shaft 133. The shaft 133 is generally constructed from polymeric materials, metals, ceramics, woods, or other suitable materials.

The cooling device 104 further includes a handle 140 slidably coupled to the shaft 133 or formed as a part of the shaft 133. The handle 140 is configured to be held by a hand of an operator. For example, the handle 140 can have a grip with grooves to improve stability of the cooling device 104 when held by the operator. The handle 140 further includes an actuator 142 that operates with the shaft 133 to move the second cooling element 130 b relative to the shaft 133. In the example shown in FIG. 2A, the actuator 142 is a lever that engages the shaft 133 to incrementally advance the second cooling element 130 b in an axial motion (arrow C) along the shaft 133.

In operation, an operator can hold the cooling device 104 in one hand by grasping the handle 140. Then, the cooling elements 130 a-b can be rotated via the mounting elements 136 a-b to achieve a desired orientation. The operator can place the cooling device 104 having the cooling elements 130 a-b in the desired orientation proximate to the subject's skin to remove heat from a subcutaneous region of the subject 101. In one embodiment, the operator can clamp a portion of the subject's skin between the heat exchanging surfaces 131 a-b when the surfaces 131 a-b are generally parallel to each other. In another embodiment, the operator can press the heat exchanging surfaces 131 a-b against the subject's skin when the surfaces 131 a-b are generally co-planar. In certain embodiments, the operator can use thermoelectric coolers to remove heat from the subcutaneous region as described below with reference to FIG. 4. The operator can also monitor and control the treatment process by collecting measurements, such as skin temperatures, from the sensing element 135 a. By cooling the subcutaneous tissues to a temperature lower than 37° C., subcutaneous lipid-rich cells can be selectively affected. The affected cells are then resorbed into the patient through natural processes.

One expected advantage of using the cooling device 104 is that subcutaneous lipid-rich cells can be reduced generally without collateral damage to non-lipid-rich cells in the same region. In general, lipid-rich cells can be affected at low temperatures that do not affect non-lipid-rich cells. As a result, lipid-rich cells, such as those forming the cellulite, can be affected while other cells in the same region are generally not damaged even though the non-lipid-rich cells at the surface are subject to even lower temperatures. Another expected advantage of the cooling device 104 is that it is relatively compact because the cooling device 104 can be configured as a handheld device. Yet another advantage is that the cooling device can be applied to various regions of the subject's body because the two cooling elements 130 a-b can be adjusted to conform to any body contour. Another expected advantage is that by pressing the cooling device 104 against the subject's skin, blood flow through the treatment region can be reduced to achieve efficient cooling. Still another expected advantage is that the power requirement is reduced for each of the cooling elements 130 a-b because heat is removed from the skin through the two heat exchanging surfaces 131 a-b instead of a single cooling element.

The first and second cooling elements 130 a-b can have many additional embodiments with different and/or additional features without detracting from the operation of both elements. For example, the second cooling element 130 b may or may not have a sensing element proximate to the second heat exchanging surface 131 b. The second cooling element 130 b can be constructed from a material that is different from that of the first cooling element 130 a. The second mounting base 134 b can have a shape and/or a surface configuration different from that of the first mounting base 134 a. The first cooling element 130 a can be rotatable, but the second cooling element 130 b may be non-rotatable.

FIG. 2C is an alternative example of the cooling device 104 in accordance with one example of the invention for use in the system 100. This alternative example, and those alternative examples and other alternatives described herein, are substantially similar to previously-described examples, and common acts and structures are identified by the same reference numbers. Only significant differences in operation and structure are described below. In this example, the cooling device 104 includes a support 128 having a portion 129 b and a portion 160, a cooling element 130 b located at the portion 129 b, and a reciprocating element 164 located at the portion 160. The cooling device 104 is generally configured to be a handheld unit for manual operation, and/or it can be strapped or otherwise configured to be releasably attached to the subject. In this example, the reciprocating element 164 can be configured to move along the support 128 and/or rotate to position the reciprocating element 164 to apply pressure to the treatment area during operation. The reciprocating element 164 can include a housing 166 and a sensing element 162. The housing 166 can be constructed from polymeric materials, metals, ceramics, woods, and/or other suitable materials. The example of the housing 166 shown in FIG. 2C is generally rectangular, but can have any other desired shape.

The reciprocating element 164 can also include at least one sensing element 162 proximate to the skin (not shown). The sensing element 162, for example, can be generally flush with a face of the reciprocating element 164. Alternatively, it may be recessed or protrude from the surface. The sensing element 162 can include a temperature sensor, a pressure sensor, a transmissity sensor, a bioresistance sensor, an ultrasound sensor, an optical sensor, an infrared sensor, or any other desired sensor, as discussed in detail herein.

FIG. 3A is an end view and FIG. 3B is a side elevation view of the embodiment of the cooling device 104 shown in FIGS. 2A and 2B. Like reference symbols refer to like features and components in FIGS. 1-3B. In one aspect, the first cooling element 130 a can include a fluid chamber 150 a within the housing 139 a. The fluid chamber 150 a can be in fluid communication with the fluid ports 138 a-b such that fluid can circulate through the fluid chamber 150 a. Optionally, the fluid chamber 150 a can include one or more flow elements to promote uniform or otherwise controlled fluid circulation through the fluid chamber 150 a. For example, the fluid chamber 150 a can include baffles, static mixers, nozzles, ventures, orifices or any combination of these flow elements. The fluid chamber 150 a can be configured to accept fluid coolants, such as water, glycol, a synthetic heat transfer fluid, oil, refrigerants, air, carbon dioxide, nitrogen, and argon.

The first interface member 132 a can be a diffuser disposed in the housing 139 a such that the first heat exchanging surface 131 a faces away from the fluid chamber 150 a. The first interface member 132 a is accordingly in thermal communication with the fluid chamber 150 a to transfer heat between the first heat exchanging surface 131 a and the fluid chamber 150 a. In one embodiment, the interface member 132 a is releasably attached to the housing 139 a using mechanical fasteners to allow access to the fluid chamber 150 a or the backside of the first interface member 132 a. The sensing element 135 a can be placed in the first interface member 132 a at least proximate to the first heat exchanging surface 131 a as described above.

The first cooling element 130 a can also include a pressure sensor 152 between the housing 139 a and the mounting element 136 a to sense the pressure exerted by the first cooling element 130 a against the subject. In one embodiment, the first interface member 132 a can be attached to the housing such that pressure applied against the first heat exchanging surface 131 a is transferred via the housing 139 a to the pressure sensor 152. The pressure sensor 152 can alternatively be configured to sense the pressure in the fluid chamber 150 a for monitoring pressure variations in the fluid chamber 150 a. Alternatively, the pressure could be inferred from force and the known contact area of the cooling elements. For example, the sensor 152 can be any type of load-sensitive pressure sensing element such as a load cell (model #LC201-25) produced by OMEGA Engineering, Inc. in Stamford, Conn. Direct pressure measurement could also be performed by placing a pressure measurement membrane directly at the interface between the cooling element and the skin.

The second cooling element 130 b can also include a second interface member 132 b similar to that of the first cooling element 130 a. As shown in FIG. 3B, the second interface member 132 b does not have a sensing element proximate to the second heat exchanging surface 131 b. However, the second cooling element 130 b can include a temperature sensor and/or a pressure sensor similar to the first cooling element 130 a. In addition, the first and second cooling elements 130 a-b can be configured to have different sensing elements.

FIG. 3B illustrates additional aspects of an example of the handle 140 and actuator 142. The actuator 142 can further include a spring 146 that drives the lever against a stop 147 fixedly attached to the second mounting base 134 b. In operation, when an operator moves the actuator 142 toward the handle 140, the actuator 142 overcomes the force from the spring 146 to move the second mounting base 134 b along the shaft 133 toward the first mounting base 134 a. When the operator releases the actuator 142, the spring 146 drives the actuator 142 back in contact with the stop 147.

The cooling device 104 can further include a locking element that releasably holds the first and second cooling elements 130 a-b in a fixed relative position. The locking element can be a catch 144 having a slot 143 through which the shaft 133 extends. A locking spring 145 forces the catch 144 to be at an angle relative to the shaft 133 such that the catch 144 frictionally engages the shaft 133. In operation, when an operator moves the actuator 142 toward the handle 140, the shaft 133 overcomes the force from the locking spring 145 to move the second mounting base 134 b toward the first mounting base 134 a. When the operator releases the actuator 142, the locking spring 145 drives the catch 144 away from the actuator 142 such that the catch 144 re-engages the shaft 133 to prevent the shaft 133 from slidably moving through the slot 143. When the operator moves the catch 144 toward the handle 140, the catch 144 disengages the shaft 133 to allow the shaft 133 to slide through the slot 143 so that the second cooling element 130 b can be moved away from the first cooling element 130 a. When the operator releases the catch 144, it re-engages the shaft 133 to prevent the shaft 133 from moving.

D. Method of Applying Cooling Devices with Rotatable Cooling Elements

In operation, the angle between the first and second heat exchanging surfaces 131 a-b is selected by rotating the first and second cooling elements 130 a-b. The angle between the cooling elements 130 a-b is often selected to conform the first and second heat exchanging surfaces 131 a-b to various body contours of the subject 101 and/or a desired clamping arrangement. In the embodiment shown in FIG. 2A, the angle between the first and second heat exchanging surfaces 131 a-b can be generally 0°, i.e., the first and second heat exchanging surfaces 131 a-b are generally parallel to each other for clamping a treatment region between the first and second cooling elements 130 a-b. In the embodiment shown in FIG. 2B, the angle can be 180°, i.e., the first and second heat exchanging surfaces 131 a-b are generally co-planar. In other embodiments, the angle can be any angle between generally 0° and generally 180°, as would be recognized by one skilled in the art.

After configuring the cooling elements 130 a-b, an operator places the cooling device 104 proximate to the skin of the subject 101. In the embodiment shown in FIG. 2A (where the angle is generally 0°), the cooling elements 130 a-b are initially spaced apart from each other by a first distance in which a fold of the patient's skin is placed. The operator then pulls the actuator 142 to drive the second cooling element 130 b toward the first cooling element 130 a until the fold of skin is clamped between the cooling elements 130 a-b. The clamping force can be increased by using the actuator 142 or decreased by disengaging the catch 144. Optionally, the pressure sensor 152 can be used to sense the clamping pressure applied via the first interface member 132 a, and the sensed clamping force can be processed by the processing unit 114 and displayed on the output device 120. The clamping force can then be adjusted based on the displayed values. The clamping force, for example, can be higher than the systolic pressure in the fold of skin to impede or block the blood flow into the fold of skin. As explained in more detail below, applying such pressure enables more effective cooling of the target region because there is less blood flow to transfer core body heat to the target region.

In another embodiment shown in FIG. 2B (where the angle is generally 180°), placing the cooling device 104 can include pressing the first and second heat exchanging surfaces 131 a-b against an area of the subject's skin. In one aspect, the applied pressure on the subject's skin can be greater than or equal to the systolic blood pressure in the subject's skin. Optionally, the pressure sensor 152 can be used to sense the pressure applied via the first interface member 132 a, and the pressure applied to the subject's skin can be adjusted as described above.

Clamping a fold of the subject's skin or pressing against the skin can be advantageous to achieve efficient cooling. In general, the subject 101 has a body temperature of about 37° C., and the blood circulation is one mechanism for maintaining a constant body temperature. As a result, blood flow through the dermis and subcutaneous layer of the region is a heat source that counteracts the cooling of the sub-dermal fat. As such, if the blood flow is not reduced, cooling the subcutaneous tissues would require not only removing the specific heat of the tissues but also that of the blood circulating through the tissues. Thus, reducing or eliminating blood flow through the target region can improve the efficiency of cooling and avoid excessive heat loss from the dermis and epidermis.

By cooling the subcutaneous tissues to a temperature lower than 37° C., subcutaneous lipid-rich cells can be selectively affected. In general, the epidermis and dermis of the subject 101 have lower amounts of unsaturated fatty acids compared to the underlying lipid-rich cells forming the subcutaneous tissues. Because non-lipid-rich cells usually can withstand colder temperatures better than lipid-rich cells, the subcutaneous lipid-rich cells can be selectively affected while maintaining the non-lipid-rich cells in the dermis and epidermis. An exemplary range for the cooling elements 130 a-b can be from about −20° C. to about 20° C., preferably from about −20° C. to about 10° C., more preferably from about −15° C. to about 5° C., more preferably from about −10° C. to about 0° C.

The lipid-rich cells can be affected by disrupting, shrinking, disabling, destroying, removing, killing, or otherwise being altered. Without being bound by theory, selectively affecting lipid-rich cells is believed to result from localized crystallization of highly saturated fatty acids at temperatures that do not induce crystallization in non-lipid-rich cells. The crystals can rupture the bi-layer membrane of lipid-rich cells to selectively necrose these cells. Thus, damage of non-lipid-rich cells, such as dermal cells, can be avoided at temperatures that induce crystal formation in lipid-rich cells. Cooling is also believed to induce lipolysis (e.g., fat metabolism) of lipid-rich cells to further enhance the reduction in subcutaneous lipid-rich cells. Lipolysis may be enhanced by local cold exposure, inducing stimulation of the sympathetic nervous system.

In certain embodiments, once a desired temperature is achieved, the temperature of the region can be maintained for a pre-determined period of time. The cooling cycle can be terminated by separating the heat exchanging surfaces 131 a-b from the skin. After a certain period of time, the cooling device 104 can be reapplied to the same portion of the skin as described above until a desired reduction in lipid-rich cells is achieved. In another embodiment, the cooling device 104 can be applied to a different portion of the skin as described above to selectively affect lipid-rich cells in a different subcutaneous target region.

One expected advantage of several of the embodiments described above is that the cooling device 104 can selectively reduce subcutaneous lipid-rich cells without unacceptably affecting the dermis, epidermis and/or other tissues. Another expected advantage is that the cooling device 104 can simultaneously selectively reduce subcutaneous lipid-rich cells while providing beneficial effects to the dermis and/or epidermis. These effects may include: fibroplasias, neocollagenesis, collagen contraction, collagen compaction, collagen density increase, collagen remodeling, and acanthosis (epidermal thickening). Another expected advantage is that the cooling device 104 can conform to various body contours of a subject by rotating the first and second cooling elements 130 a-b to achieve a desired orientation. Yet, another expected advantage is that the cooling device 104 can be configured as a handheld device for ease of operation. Furthermore, another expected advantage is that the system 100 with the handheld cooling device 104 and the rack mounted processing unit 114 and cooling unit 106 are compact and efficient such that the method described above can be administered in an outpatient clinic or a doctor's office instead of in a hospital.

E. Cooling Devices with Thermoelectric Cooling Elements

FIG. 4 is a side elevation view of a cooling device 204 in accordance with another example of the invention. In this example, several components of the cooling device 204 are similar to the components of the cooling device 104 described above. As such, like reference symbols refer to like features and components in FIGS. 1-4. In this example, the cooling device 204 includes cooling elements 230 a-b having thermoelectric cooling elements configured to reduce the temperature of a subcutaneous region of the subject 101 for selectively affecting lipid-rich cells in the region.

The first cooling element 230 a can include a housing 239 a and a plurality of fluid ports 238 a coupled to the fluid lines 108 a-b. The first cooling element 230 a can also include a first interface member 232 a having a first heat exchanging surface 231 a and a first fluid chamber 250 a. The first interface member 232 a can be constructed with a thermally conductive material at the first heat exchanging surface 231 a, but the first interface member 232 a can have an insulating portion 211 a around the first heat exchanging surface 231 a.

The first cooling element 230 a can further include a thermoelectric cooler 214 a, such as a Peltier-type element, having a first side 213 a and a second side 215 a. The first side 213 a is in thermal communication with the first interface member 232 a, and the second side 215 a is in thermal communication with the fluid chamber 250 a. The thermoelectric cooler 214 a can be connected to an external power supply (not shown) to transfer heat between the first side 213 a and the second side 215 a. The thermoelectric cooler 214 a can be a single Peltier-type element or an array of Peltier-type elements. One suitable thermoelectric cooler is a Peltier-type cooling element (model # CP-2895) produced by TE Technologies, Inc. in Traverse City, Mich.

By applying power to the thermoelectric cooler 214 a, heat can be effectively removed from the subject's skin via the first heat exchanging surface 231 a to a circulating fluid in the fluid chamber 250 a. For example, applying a current to the thermoelectric cooler 214 a can achieve a temperature generally below 37° C. on the first side 213 a of the thermoelectric cooler 214 a to remove heat from the subject 101 via the first heat exchanging surface 231 a. The thermoelectric cooler 214 a transfers the heat from the first side 213 a to the second side 215 a where the heat is then transferred to the circulating fluid. The cooling unit 106 then removes the heat from the circulating fluid.

The thermoelectric coolers 214 a-b can be configured to withdraw a sufficient amount of heat quickly from the subject 101 without using a high-voltage power supply for the cooling unit 106. In one example, the interface members 232 a-b can be a generally rectangular aluminum plate with dimensions of about 3 cm×4 cm×1 cm, and the thermoelectric coolers are Peltier-type thermoelectric elements rated at about 160 Watts. As such, the cooling device 204 can cool a portion of the subject's skin (approximately 3 cm×4 cm×5 cm) from a temperature of about 37° C. to about −20° C. quickly and effectively. The cooling unit 106 can use a normal voltage power supply (e.g., 120 VAC) because the power consumption is not excessive. This enables the system to be used in hospitals, clinics, and small offices without more costly high voltage electrical systems.

The cooling device 204 can also be in electrical communication with the processing unit 114, and the cooling temperature can be automatically adjusted by the processing unit 114. The temperature of the first heat exchanging surface 231 a can be sensed by the sensing element 135 a. The sensed electrical signal can be converted by the processing unit 114 into a process value for the temperature. In one embodiment, the processing unit 114 can include a Proportional, Integral and Derivative controller, which can adjust the power output to the thermoelectric cooler 214 a to achieve and/or maintain the desired temperature.

F. Cooling Devices with Curved Heat Exchanging Surfaces

FIGS. 5A and 5B are a side elevation view of a cooling device 304 in accordance with another example of the invention. Several components of the cooling device 304 are similar to those of the cooling device 104. As such, like reference symbols refer to like features and components in FIGS. 1-5B. In this example, the cooling device 304 includes cooling elements 330 a-b with curved heat exchanging surfaces 331 a-b as described in more detail below.

The first cooling element 330 a can include a housing 339 a, a fluid chamber 350 a, and fluid ports 338 a coupled to the fluid lines 108 a-b. The first cooling element 330 a can further include an interface member 332 a having a curved heat exchanging surface 331 a and a back surface 333 a. The curved heat exchanging surface 331 a can be either concave or convex, and the back surface 333 a can be either generally planar or similarly curved as the heat exchanging surface 331 a. The first cooling element 330 a can further include a thermoelectric cooler 314 a proximate to the back surface 333 a and in thermal communication with the fluid chamber 350 a for removing heat via the heat exchanging surface 331 a.

The second cooling element 330 b in FIGS. 5A and 5B include similar features as the first cooling element 330 a. Specifically, the second cooling element 330 b includes a concave heat exchanging surface 331 b with generally the same curvature as that of the heat exchanging surface 331 a. However, the second cooling element 330 b can also have a heat exchanging surface 331 b that is concave but with a different curvature from that of the first heat exchanging surface 331 a, or the heat exchanging surface 331 b can be generally planar or convex. As such, the first and second heat exchanging surfaces 331 a-b can have any combination of the different surface curvatures.

The first and second heat exchanging surfaces 331 a-b operate generally similarly to the heat exchanging surfaces 131 a-b of the cooling device 104. Particularly, the two curved first and second heat exchanging surfaces 331 a-b can transfer heat to/from a portion of the skin when the portion of the skin is placed proximate to the first and second heat exchanging surfaces 331 a-b. The curved surfaces 331 a-b can enhance heat transfer from the portion of the skin as described below in more detail.

In operation, the cooling device 304 can be placed proximate to the skin of the subject 101 such that a portion of the skin is placed against the two curved heat exchanging surfaces 331 a-b. Then the portion of the skin can be either clamped, strapped or pressed as described above with reference to FIGS. 2 and 3. In one embodiment, a voltage is applied to the thermoelectric coolers 314 a-b to cool a subcutaneous region of the patient as described above with reference to FIG. 4. In further embodiments, other cooling methods can also be used, such as by convection, radiation, conduction, or any combination of these methods.

One advantage of the curved heat exchanging surfaces 331 a-b is that the curved surfaces may focus the heat transfer in the subcutaneous region. For example, when both the heat exchanging surfaces are concave, the concave surfaces can focus heat removal from the skin between the two heat exchanging surfaces 331 a-b. When both the heat exchanging surfaces are convex, the convex surfaces can spread the skin between the two heat exchanging surfaces 331 a-b such that the distance between the subcutaneous layer of the skin and the heat exchanging surfaces 331 a-b is reduced. The reduced distance may enhance heat transfer because the thermal conductivity of the epidermis and dermis decreases with decreased thickness.

G. Computing System Software Modules

FIG. 6 illustrates a functional diagram showing exemplary software modules 440 suitable for use in the processing unit 114. Each component can be a computer program, procedure, or process written as source code in a conventional programming language, such as the C++ programming language, and can be presented for execution by the CPU of processor 442. The various implementations of the source code and object and byte codes can be stored on a computer-readable storage medium or embodied on a transmission medium in a carrier wave. The modules of processor 442 can include an input module 444, a database module 446, a process module 448, an output module 450, and optionally, a display module 451. In another embodiment, the software modules 440 can be presented for execution by the CPU of a network server in a distributed computing scheme.

In operation, the input module 444 accepts an operator input, such as process setpoint and control selections, and communicates the accepted information or selections to other components for further processing. The database module 446 organizes records, including operating parameters 454, operator activities 456, and alarms 458, and facilitates storing and retrieving of these records to and from a database 452. Any type of database organization can be utilized, including a flat file system, hierarchical database, relational database, or distributed database, such as provided by a database vendor such as Oracle Corporation, Redwood Shores, Calif.

The process module 448 generates control variables based on the sensor readings 456, and the output module 450 generates output signals 458 based on the control variables. For example, the output module 450 can convert the generated control variables from the process module 448 into 4-20 mA output signals 458 suitable for a direct current voltage modulator. The processor 442 optionally can include the display module 451 for displaying, printing, or downloading the sensor readings 456 and output 458 via devices such as the output device 120. A suitable display module 451 can be a video driver that enables the processor 442 to display the sensor readings 456 on the output device 120.

Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in a sense of “including, but not limited to.” Words using the singular or plural number also include the plural or singular number respectively. When the claims use the word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.

The above detailed descriptions of embodiments of the invention are not intended to be exhaustive or to limit the invention to the precise form disclosed above. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative embodiments may perform steps in a different order. The various embodiments described herein can be combined to provide further embodiments.

In general, the terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification, unless the above detailed description explicitly defines such terms. While certain aspects of the invention are presented below in certain claim forms, the inventors contemplate the various aspects of the invention in any number of claim forms. Accordingly, the inventors reserve the right to add additional claims after filing the application to pursue such additional claim forms for other aspects of the invention. 

1-41. (canceled)
 42. A cooling system for affecting subcutaneous lipid-rich cells of a subject, comprising: a cooling device having an unlocked state for reconfiguring the cooling device for accommodating different size folds of tissue of the subject and a locked state for receiving and holding a fold of tissue, the cooling device including rigid concave tissue-contact regions facing one another to surround opposite sides of the fold of tissue, the cooling device is operable to remove heat from the lipid-rich cells in the fold of tissue in thermal communication with the rigid concave tissue-contact regions to cool and thermally affect the lipid-rich cells while non-lipid rich cells in skin of the fold of tissue are not substantially affected.
 43. The cooling system of claim 42, further comprising a cooling unit in thermal communication with the cooling device and configured to provide temperature-controlled coolant to the cooling device.
 44. The cooling system of claim 42, wherein the cooling device includes a plurality of independently-controllable cooling elements each operable to cool the fold of tissue independent of the configuration of the cooling device.
 45. The cooling system of claim 42, wherein opposing portions of the cooling device are configured to initially contact the patient and move away from each other, and the opposing portions are configured to automatically move toward one another as the fold of tissue is moved into the cooling device.
 46. The cooling system of claim 42, wherein the cooling device in the locked state is configured to automatically move to toward a flared entrance configuration when the cooling device is initially pressed against the subject and is configured to automatically move toward a tissue retention configuration as the fold of tissue is moved into the cooling device.
 47. The cooling system of claim 42, wherein when the cooling device is in the locked state, the cooling device defines a tissue-receiving entrance that is configured to widen to facilitate insertion of the fold of tissue into and through the tissue-receiving entrance.
 48. The cooling system of claim 42, wherein the cooling device includes a manually-operated catch rotatable to change the cooling device from the locked state to the unlocked state.
 49. The cooling system of claim 42, wherein the cooling device further includes: a first temperature sensor positioned to detect a temperature at a first side of the fold of tissue, and a second temperature sensor positioned to detect a temperature at a second side of the fold of tissue opposite the first side.
 50. The cooling system of claim 42, wherein the cooling device has a concave heat-exchanging surface extending along a length of a tissue-receiving gap defined by the cooling device.
 51. The cooling system of claim 42, wherein the cooling device includes a locking element configured to lock the cooling device in different configurations.
 52. The cooling system of claim 42, wherein portions of the cooling device are located on opposite sides of an entrance to a gap between the rigid concave tissue-contact regions, wherein the portions are configured to move away from each other and toward a flared configuration when the fold of tissue is moved through the entrance.
 53. A cooling system for affecting subcutaneous lipid-rich cells of a subject, comprising: a cooling device having rigid concave tissue-contact regions positioned to thermally contact opposite sides of a fold of tissue held in the cooling device and thermoelectric cooling elements configured to independently cool opposite sides of the fold of tissue, the cooling device having an unlocked state for reconfiguring an entrance of the cooling device to accommodate the fold of tissue of the subject and a locked state for receiving and then holding the fold of tissue; and a controller in communication with the cooling device and programmed to cause the cooling device to remove heat from lipid-rich cells in the fold of tissue in thermal communication with the rigid concave tissue-contact regions so as to thermally affect the lipid-rich cells while non-lipid rich cells in skin of the fold of tissue are not substantially affected.
 54. The cooling system of claim 53, further comprising a cooling unit in thermal communication with the cooling device and configured to provide temperature-controlled coolant to the cooling device.
 55. The cooling system of claim 53, wherein opposing portions of the cooling device are positioned to initially contact the subject and are configured move away from each other when the cooling device is pressed against the subject, and the opposing portions are configured to automatically move toward one another to help hold the fold of tissue in the cooling device. 